For imaging blood vessels with an enhanced contrast with a contrast agent, a contrast-enhanced X-ray image diagnostic apparatus is known. The apparatus includes, for example, an X-ray tube and an FPD (flat panel detector) or an I.I. (image intensifier), which are each provided on both ends of a generally C-shaped support (C-arm), and an image processing section. The contrast-enhanced X-ray image diagnostic apparatus is also generally referred to as an angiographic apparatus, which can be used by doctors for diagnosis and treatment (medical examination) such as catheter insertion to a patient as an object and for X-ray photography.
Generally, for observation of collateral circulations and their peripheral blood vessels, there is a medical image pickup technology with X-ray image diagnostic apparatuses, X-ray CT (computed tomography) apparatuses, and MRI (magnetic resonance imaging) apparatuses.
As a conventional technology, there is a technology of obtaining images that show various structures of interested organizations such as blood vessels in an easily understandable way.
In the conventional technology, collateral circulations, which are extracted based on angiographic images (including non-contrast enhanced MRA images obtained without a contrast agent) collected by medical diagnostic imaging apparatuses such as X-ray CT apparatuses, MRI apparatuses and contrast-enhanced X-ray image diagnostic apparatuses, are locally concentrated, and therefore, they are extracted on images as clouds typically seen in the case of moyamoya disease (occlusive disease in circle of Willis). Under these circumstances, the collateral circulations have been an obstacle in observing peripheral vessel structures with use of angiographic images. Moreover, blood vessels that position downstream from a collateral circulation are often shown as minute streams on images as their blood flow rate is low. Accordingly, due to the presence of the collateral circulation, it has been difficult to grasp peripheral vessel structures.